Cocktail shaker



FIG. 1 is a perspective view of a cocktail shaker showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof.

FIG. 6 is an enlarged top plan view thereof; and,

FIG. 7 is an enlarged bottom plan view thereof. 

The ornamental design for a cocktail shaker, as shown and described. 